Drill bit assembly



June 27, 1967 E. s. CREEL DRILL BIT ASSEMBLY 2 Sheets-Sheet 1 fi////x///Filed Oct. 16, 196

49 F'/G. a

INVENTOR. fie/V557 a 4 ATTOINEYS DRILL BIT ASSEMBLY Filed Oct. 16, 19642 Sheets-Sheet 2 INVENTOR.

[EA 57 s, 679554,

United States Patent 3,327,794 DRILL BIT ASSEMBLY Ernest S. Creel,Odessa, Tex. (7621 Beaver Drive, Fort Worth, Tex. 76118) Filed Oct. 16,1964, Ser. No. 404,273 9 Claims. (Cl. 175-412) This invention relates tothe general field of drilling equipment and, more specifically, thepresent invention relates to improvements in such equipment whereindrill bits having removable cutting blades are utilized in the drillingof a well.

As a general rule, bits of the type to which reference has been made areprovided with blades which extend below the bit heads and, by virtue ofheavy torque loads which are applied during the drilling operation, thecutting edges of the teeth of the blade are frequently broken or theblades, themselves, bent, whereby it becomes necessary to halt thedrilling operation. This is necessarily timeconsuming and expensive.

When it becomes necessary to provide the replacement of the blades ithas frequently been found that for mechanical reasons it is verydifiicult to separate the drill bit heads from the sub to which they areconnected with out still additional loss of time and, additionally, theassembly and disassembly of the blades from the head is cumbersome,unwieldly, and difiicult in carrying out.

Thus, one of the primary objects of this invention is to provide animproved connector means between the drill bit head and the sub whichovercome the above objectionable features now found in the prior artwhile maintaining a safe and positive connection therebetween during theoperation thereof.

A further object of this invention is to provide connector or couplingmeans between the drill bit head and its associated sub which positivelylocks the blades to the drill head and wherein no special tools arerequired to effect a disassembly therebetween.

This invention contemplates, as still another object thereof, theprovision of connector or coupler means for connecting a drill bit headwith a sub wherein the means is non-complex in construction andassembly, comparatively inexpensive to manufacture and maintain, andwhich is durable and rugged in use.

Other and further objects and advantages of the instant invention willbecome more evident from .a consideration of the following specificationwhen read in conjunction with the annexed drawings, in which:

FIGURE 1 is a side elevational view of a drill bit embodying theconnector or coupling means of the present invention;

FIGURE 2 is a medial cross-sectional view, FIGURE 2 being takensubstantially on the vertical plane of line 2-2 of FIGURE 1, looking inthe direction of the arrows;

FIGURE 3 is a detail cross-sectional view, FIGURE 3 being takensubstantially on the horizontal plane of line 33 of FIGURE 2, looking inthe direction of the arrows;

FIGURE 4 is an exploded perspective view showing the details of theconnector or coupler means according to this invention;

FIGURE 5 is a vertical cross-sectional view similar to FIGURE 2, butillustrating a second embodiment of this invention; and

FIGURE 6 illustrates, in perspective, a blade utilized in the secondembodiment of the invention.

Referring now more specifically to the drawings, reference numeral 10designates, in general, a hollow elongated substantially tubular subhaving an upper end 12 internally threaded as at 14 adapted forconnection to the lower end of a drill string (not shown). The oppositeor lower end 16 of the sub 10 is formed with external left-hand threads18 and internal right-hand threads 20.

Reference numeral 22 denotes a drill bit adapted for detachableconnection with the lower end of the sub 10. The drill bit 22 includesan enlarged head 24, and an integral axially-aligned elongated hollowcylindrical member 26. The upper or outer end of the cylindrical member26 is formed with inwardly-extending external threads 28 which extendinwardly to a stop collar 30, and the cylindrical member 26, over thatportion thereof extending between the stop collar 30 and the head 24, isreduced in diameter to provide an elongated cylindrical neck 32 and acircumferential shoulder 33. Also formed in the head 24 adjacent theupper end thereof is a downwardly and inwardly-inclined upwardly-facingV-shaped groove 34 having a side thereof opening into the plane of theshoulder 33.

The head 24 is also provided with a plurality of axially andradially-extending circumferentially-spaced slots 35, and the usualaxial water or air passage 36 which opens into the cylindrical member26.

Reference numerals 38 indicate a plurality of identical blades each ofwhich includes a substantially fiat rectangular vertical shank 40 havingcutting teeth 42 at the lower end thereof. As is seen in the drawings,the upper inner edge of each blade 38 terminates in an integral arcuateplate 44, the plate 44 tapering in its thickness from its lower edge 45'to its upper edge 45, and the lower inner edge of each shank 40 projectsinwardly as at 46. The lower inner edges of each blade 38 terminate in astabilizing lug 48 of conventional construction.

Reference numeral 50 denotes an elongated substantially hollowcylindrical connector or coupling sleeve internally-threaded at 52 atits upper end, the lower end 54 thereof being reduced in diameter andterminating in a beveled edge 56. The connector or coupling sleeve isformed with a plurality of radially-extending circumferentially-spacedslots 58.which extend upwardly from the lower beveled edge 56 forsubstantially the axial length of the lower end 54 to give rise to thesubstantially arcuate flanges 59. The internal diameter of the flanges59 taper downwardly, as is seen in FIGURE 2, to serve a function to bedescribed.

To assemble the above-described device, the sleeve 50 is first threadeddown on the lower end 16 of the sub 10, and it should be remembered thatthe threads 18 are lefthand and that the threads 52 complement the same.When this threading has been completed, the hollow cylindrical member 26is partially threaded into the lower end 16, it also being rememberedthat the threads 20' are right-hand and that the threads 28 complimentthe same. This threading continues until the lower end 30' of the stopcollar 30 is withdrawn partially behind the flanges 59. The slots 35, 38are then brought into alignment with one another and the blades 38 arenext assembled. In the embodiment shown in FIGURES 1 to 3, inclusive,the upper edge 45 of the arcuate plate 44 is substantially flush withthe upper end 40' of the shank 40. Thus, to seat the blades 38 with thearcuate plates 44 engaging against the neck 32 with portions of theshank 40 seating within the aligned slots 35, 58 it is necessary topivot the upper edges 45 over the beveled edges 56 to cause the upperend 49 of each blade 38 to enter its respective slot 58 and then torelease the blades 38 so that the lower ends 45 thereof engage and rideon the shoulder 33, and the shanks 40 engage within their respectiveslots 58 with the ends 46 thereof engaging over the lower end of thehead 24.

With the blades 38 in place and with the shanks 40 thereof locking withthe sleeve 50 and the head 24, a backing-off of the sleeve 50 willeffect relative axial movement of the sleeve 50 toward the head 24 and,vice versa. That is, each will move axially of the sub 10 in equalincrements, but in opposite directions. This relative movement continuesuntil the flanges 59 completely embrace the arcuate plates 44 and untilthe beveled edges 56 thereof engage and lock within the groove 34. Thecomponent elements of the device are now in their respective positionsas is shown in FIGURES l to 3, inclusive. To disassemble the blades 38from the device it is only necessary to turn the sleeve 50 in thereverse direction, causing the head 24 and the sleeve 50 to move awayfrom one another and the arcuate plates 44 to become exposed after whichthe blades 38 may be removed and replaced.

It should here be noted that in reducing the diameter of the cylindricalmember 26 to form the neck 32, sulficient clearance is obtained betweenthe neck 32 and the flanges 58 to accept the arcuate plates 44.

The above-described connector or coupling device is shown in conjunctionwith conventional blades 38. The disclosure was so made in order to showthe ready adaptability of the connector or coupling to equipmentpresently available on the open market. However, the conventional bladeis a little troublesome in assembling with the device since, as pointedout above, the arcuate plates 44 must be tipped over the flanges 56 inorder to seat the upper ends 40' of the shanks 40 within the slots 58.To overcome this minor difiiculty and to provide still other advantages,the instant invention proposes to utilize in the described connector orcoupling device the blades shown in FIG- URES and 6. To utilize theblades shown in FIGURES 5 and 6, the coupler device must be altered inbut a minor respect.

Since the coupling devices of both embodiments of the invention aresubstantially identical, and the same is also true with respect to theblades, the same reference numerals will be employed, increased by 100to diiferentiate elements of the second embodiment of the invention fromtheir counterparts found in the first embodiment thereof. Thus, andreferring to FIGURE 5 of the drawings, the only change in theconstruction of the coupling device resides in the formation of acircumferential groove 200 in the neck 132, the groove 200 beingadjacent to but spaced from the stop collar 130.

Referring now specifically to FIGURE 6, it will be noted that thearcuate plate 144 has been shifted downwardly on the inner edge of theshank 140 to provide a clearance 300 between the upper end 145 thereofand the upper end 140 of the shank 140. Additionally, the plate 144 isprovided with an arcuately-shaped rib 302 that projects laterally fromthe concave side of the arcuate plate 144, the rib 302 beingsubstantially parallel to the upper and lower ends 145, 145' of theplate 144, and being adjacent to but spaced below the end 145.

To assemble the blades 138' with the coupling device it is no longernecessary to tilt the blades in the manner described above since theclearance required through the use of the blade 38 due to the presenceof the upper edge 145 substantially flush with the upper end 40 of theshank 40 is obviated. This clearance is clearly shown in FIG URE 2wherein appreciable space is seen to exist between the upper end 45 ofeach blade 38 and the inner end of its associated slot 58. Thus, thearcuate plates 144 may be fit flush against the neck 132 with the upperend of each blade 140 fitting against the inner end of each of itsrespective slots 58 as is shown in FIGURE 5. The rib 302, of course,enters the circumferential groove 200. The blade 138 is constructed ofsuch vertical length that the end 145' will seat against the shoulder133 when the rib 302 is engaged within the groove 200. The taper on theblades 144 taken in conjunction with the taper on the flanges 59cooperate to normally hold the end 140' out of engagement with the innerend of the slot 58. This is necessary since the sleeve 50 must bepermitted to travel in order to keep the blades tight as the componentelements of the invention wear.

In all other respects, the two embodiments of this invention areidentical.

Having described and illustrated a plurality of embodiments of thisinvention, it will be understood that the same are offered merely by wayof example, and that this invention is to be limited only by the scopeof the appended claims.

What is claimed is:

1. An article of manufacture comprising a drill bit, said drill bitincluding an elongated substantially hollow cylindrical member having anenlarged head at one end thereof, said enlarged head having a pluralityof circumferentially spaced axially extending blade receiving slotsformed therein, said slots extending inwardly from the outer peripheralside of said enlarged head, the other end of said cylindrical memberhaving threads formed thereon terminating in spaced relation relative tosaid head, said threaded other end providing means for connection to asub, that portion of said cylindrical member extending between said headand said threads being necked down, and a stop collar on saidcylindrical member between said neck and said threads.

2. A coupling device for connecting a drill bit having a drill head witha drill string, said coupling device including an elongatedsubstantially hollow sub, first means on said sub movable axiallythereof toward and away from said sub, second means connecting saiddrill bit in said sub to move said head axially toward and away fromsaid sub, said first and second means being operable to simultaneouslymove said first means and said head toward and away from one another,and third means connecting said first means with said second means.

3. A drill bit assembly including an elongated substantially hollowtubular sub, means on one end of said sub for connection with a drillstring, the other end of said sub having internal and external threadsof, respectively, opposite hand, an elongated substantially hollowinternally-threaded cylindrical sleeve having an end thereof threadedlyengaging said external threads of said sub for movement axially thereof,the other end of said sleeve projecting axially beyond said other end ofsaid sub, a drill bit comprising an elongated substantially hollowcylindrical member having an enlarged head at one of its ends, the otherend of said cylindrical member being externally threaded for engagementwith said internal threads of said sub, and means connecting said sleevewith said head whereby rotation of said sleeve in one direction or theother elfects simultaneous axial movement of said sleeve and drill bittoward or away from one another.

4. A drill 'bit assembly for detachably connecting drilling blades witha drill stem, said assembly including an elongated substantially hollowtubular sub, means on one end of said sub for connection with a drillstring, the other end of said sub having internal and external threadsformed thereon of, respectively, opposite hand, an elongatedsubstantially hollow cylindrical sleeve having a pair of opposed openends, said sleeve being internally threaded for threaded engagement withsaid external threads of said sub whereby said sleeve may be movedaxially toward and away from said sub, the other end of said sleeveprojecting beyond the other end of said sub, a drill bit comprising anelongated substantially hollow cylindrical member having an enlargedhead at one of its ends, the other end of said cylindrical member beingexternally-threaded for threaded engagement with said internal threadsof said sub whereby said drill bit may be moved axially toward and awayfrom said sub, and means on said sleeve and said head to receive theopposed ends of said blades whereby rotation of said sleeve in onedirection or the other causes said sleeve and said head to move axiallyof said sub, simultaneously, toward or away from one another.

5. A drill bit assembly as defined in claim 4, wherein said blades eachincludes a shank and wherein said sleeve and said head are each providedwith pairs of aligned slots to receive said shanks therein whereinrotation of said sleeve in one direction will cause said drill bit torotate in the same direction to cause engagement of said other end ofsaid sleeve with said head.

6. A drill bit assembly as defined in claim 6, wherein each of saidblades is provided with an arcuate plate adapted to engage against saidcylindrical member adjacent said head, and said sleeve upon rotationthereof moves axially of said sub to cause said other end of said sleeveto embrace said arcuate plates and to engage against said head.

7. A drill bit assembly as defined in claim 6, wherein said externalthreads on said hollow cylindrical member terminate in spaced relationrelative to said head, and that portion of said cylindrical memberbetween said external threads and said head being reduced in diameter toform a neck to receive said arcuate plates thereon.

8. A drill bit assembly as defined in claim 7, wherein said other end ofsaid sleeve is beveled, and the adjacent end of said head is providedwith a V-shaped groove to lockingly receive said beveled end therein.

9. A drill bit assembly as defined in claim 8, wherein said neck isprovided with a circumferential groove and said plates are each providedwith an arcuately-shaped rib for engagement Within said groove.

References Cited UNITED STATES PATENTS CHARLES E. OCONNELL, PrimaryExaminer. N. C. BYERS, Assistant Examiner.

4. A DRILL BIT ASSEMBLY FOR DETACHABLY CONNECTING DRILLING BLADES WITH ADRILL STEM, SAID ASSEMBLY INCLUDING AN ELONGATED SUBSTANTIALLY HOLLOWTUBULAR SUB, MEANS ON ONE END OF SAID SUB FOR CONNECTION WITH A DRILLSTRING, THE OTHER END OF SAID SUB HAVING INTERNAL AND EXTERNAL THREADSFORMED THEREON OF, RESPECTIVELY, OPPOSITE HAND, AN ELONGATEDSUBSTANTIALLY HOLLOW CYCLINDRICAL SLEEVE HAVING A PAIR OF OPPOSED OPENENDS, SAID SLEEVE BEING INTERNALLY THREADED FOR THREADED ENGAGEMENT WITHSAID EXTERNAL THREADS OF SAID SUB WHEREBY SAID SLEEVE MAY BE MOVEDAXIALLY TOWARD AND AWAY FROM SAID SUB, THE OTHER END OF SAID SLEEVEPROJECTING BEYOND THE OTHER END OF SAID SUB, A DRILL BIT COMPRISING ANELONGATED SUBSTANTIALLY HOLLOW CYLINDRICAL MEMBER HAVING AN ENLARGE HEADAT ONE OF ITS ENDS, THE OTHER END OF SAID CYLINDRICAL MEMBER BEINGEXTERNALLY-THREADED FOR THREADED ENGAGEMENT WITH SAID INTERNAL THREADSOF SAID SUB WHERE SAID DRILL BIT MAY BE MOVED AXIALLY TOWARD